Aerated gas burners

ABSTRACT

An aerated gas burner jet comprising a hollow tube with at least one external axial flute the tube being adapted to fit or sit in a port of a burner, preferably a drilled-port bar burner or a circular cast-iron ring burner, so that the flow of gas through the port passes both through the hollow tube and along the flute or flutes. The stability of the gas flames is improved by the provision of a ring or washer transversely disposed to and at least partly blocking the flute or flutes, the ring or washer causing the gas stream to be split into two.

United States Patent Greaves [54] AERATED GAS BURNERS [72] Inventor: Derek Vincent Greaves, Brockhurst,

Egypt Lane, Farnham Common, England 22 Filed: Dec. 18, 1970 211 Appl. No.2 99,415

US] 3,685,949 1 Aug. 22, 1972 2,888,979 6/1959 Lindgren ..43l/349 UX Primary Examiner-Carroll B. Dority, Jr.

Attorney-Cullen, Settle, Sloman & Cantor [57] ABSTRACT An aerated gas burner jet comprising a hollow tube with at least one external axial flute the tube being adapted to fit or sit in a port of a burner, preferably a drilled-port bar burner or a circular cast-iron ring burner, so that the flow of gas through the port passes both through the hollow tube and along the flute or flutes. The stability of the gas flames is improved by the provision of a ring or washer transversely disposed to and at least partly blocking the flute or flutes, the ring or washer causing the gas stream to be split into two.

[52] US. Cl....; ..431/349, 239/558 [51] Int. Cl ..F23d 13/24 [58] Field of Search ..43 1/349; 239/558 [56] References Cited UNITED STATES PATENTS 3,574,506 4/1971 Locke. ..43 1/349 2,675,068 4/1954 Gollus et al ..43l/349 2,789,633 4/1957 Flynn ..43l/349 3 Claim, 2 Drawing Figures P'A'TENTEBmazz I972 INVENTOR DEREK VINCE WAVES ATTORNEY AERATED GAS BURNERS The present invention relates to aerated gas burners, and in particular to aerated gas burners suitable for the burning both of manufactured (town) gas and also other gases, such as natural gas (methane) and liquid petroleum gases (propane and butane).

Difficulty is experienced in obtaining satisfactory burning of mixtures of air and the said other gases in known burners, especially in the simple and widely used burners in the form of a pipe with burner ports or holes therein. This difficulty proves to stem in the main from the fact that the velocity of the air/gas mixture often turns out to be greater than the flame speed of the mixture, which results in the production of unstable flames. Another problem is the difficulty of ensuring the smooth and continuous ignition of known burners when such mixtures are employed. These problems are particularly pressing at the present time, especially in view of the increasing use of fuels such as natural gas.

It is an object of the present invention to overcome the above difficulties and to provide a simple and inexpensive method of adapting existing drilled-port bar burners and circular cast-iron ring burners to burn satisfactorily and efficiently when used with any of the aforementioned gaseous fuels, with a minimum of adjustment or alteration to the original burner should the gas supply be changed from one sort of gas to another.

Accordingly, the invention consists in an aerated gas burner jet comprising a hollow tube with at least one external axial flute, the tube being adapted to fit or sit in a port of a burner so that the flow of gas through the port passes both through the hollow tube and along the flute or flutes.

Preferably, there is a plurality of external axial flutes. In a preferred arrangement there is provided a ring transversely disposed to and at least partly blocking the or each flute so that the gas stream passing along the or each flute is split into two. The ring improves the stability of the flames and as it gives rise to an extended stable flame, it promotes the smooth ignition of the burner as a whole.

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is an axial section taken along the line 1-1 in FIG. 2 which is a plan view an aerated gas burner jet according to the invention.

In one preferred method of carrying the present invention into effect each flame port or hole of an existing circular drilled metallic burner is enlarged in diameter and a burner jet I inserted into the enlarged port. It may be inserted as a press fit in the port, or it may be provided with a small ledge or shoulder 2 which rests on the metal surrounding the enlarged flame port. The burner jet consists of a hollow, in use, vertical, metallic cylinder 3 having external vertical axial corrugations with projections 4 forming flutes 5 therebetween and a substantially parallel-sided bore internally, the projections 4 abutting the internal peripheral wall of the enlarged circular port. The burner jet 1 is fitted with a ring or washer 6 in such a manner that the inner diameter of said ring 6 partially covers the vertical corrugations of the burner jet 1 to provide a step portion between a horizontal surface of lini'ji i ffi' fifi 52%? ffifr lifvi e2 1 hiti fi burner jet having a central internal passage surrounded by a plurality of smaller fluted passages which in turn are interrupted by the ring. The diameter of the internal passage should be greater than the diameter of the original port in order to provide an increase in burner port area which is required when using gases other than town gas.

Thus to put the invention into operation in a multiport bar or ring burner the existing flame ports are enlarged and the burner jets pressed or placed into posi tion and a gas orifice in a gas/air mixing chamber in the burner changed to suit the different gas. The gas is turned on and the gas/air mixture issues from the central passages of the burner jets and also is forced through the smaller passages formed by the corrugations and the internal diameter of the enlarged port. The said gas/air mixture from the smaller passages then expands and divides substantially into two streams, one of which continues parallel to the main central passage but at a much reduced velocity, thereby providing a ring of stable flames F at the base of the main flame F,,,. The other gas/air mixture stream strikes the underside of the ring and is spread radially of the burner jet, a stable flame F being formed between the underside of the outer periphery of the ring and the horizontal surface of the burner. This flame is stable since the turbulent conditions existing at this area reduce the velocity of the air/gas mixture to a point where it is less than or equal to the flame speed.

Although in the above description there has been described the use of a plurality of burner jets fitted into the ports of the bar and ring burners, the burner jet may clearly be used in its own right as an isolated unit, the gas and air being mixed in some manner prior to being supplied to the burner jet.

1 claim:

1. Aerated gas burner jet comprising a hollow tube with at least one external axial flute the tube being adapted to fit or sit in a port of a burner so that the flow of gas through the port passes both through the hollow tube and along the flute or flutes, and in which means are provided by which the gas stream passing along the or each flute is split into two.

2. An aerated burner jet as claimed in claim 1 in which said means is a ring transversely disposed to and at least partly blocking the or each flute.

3. An aerated burner jet as claimed in claim 1 in which there is a plurality of external axial flutes. 

1. Aerated gas burner jet comprising a hollow tube with at least one external axial flute the tube being adapted to fit or sit in a port of a burner so that the flow of gas through the port passes both through the hollow tube and along the flute or flutes, and in which means are provided by which the gas stream passing along the or each flute is split into two.
 2. An aerated burner jet as claimed in claim 1 in which said means is a ring transversely disposed to and at least partly blocking the or each flute.
 3. An aerated burner jet as claimed in claim 1 in which there is a plurality of external axial flutes. 